Sodium is an essential mineral that is found in every cell of the body. It is present in all body fluids, mostly in the fluid in-between the cells, but also found in the blood. Around 50% of the body’s sodium is in these fluids and the remainder is found within the bones.
With potassium, sodium is a major mineral regulator and helps balance and distribute the fluids throughout the body and both inside and outside the cells. Both minerals help maintain normal pH levels in the body. They are both also involved in muscle contraction and expansion, and in nerve stimulation.
Sodium is also involved in oxygen transport, and keeps other minerals in the blood soluble which prevents them from accumulating in the blood. Another important function of sodium is the transport of amino acids and carbon dioxide, helping aid carbon dioxide elimination from the body. Sodium acts with chlorine to improve blood and lymph health. It also is necessary for the production of hydrochloride acid in the stomach, thereby supporting digestive function.
This necessary mineral is found in virtually all foods. Plant foods have less sodium than animal foods. Other names used on packaging for sodium include: monosodium glutamate (MSG), sodium nitrate, propionate, alginate, curate and sulfite, baking soda and baking powder.
Sodium is easily absorbed by the body in the small intestine and stomach, and is carried by the blood to the kidneys where it is filtered and returned to the blood in amounts needed to maintain the levels required by the body. Sodium requires energy to be absorbed into the body.  The adrenal hormone, aldosterone is an important regulator of the sodium levels in the body along with the autonomic nervous system and renal mechanisms. Absorption and excretion of sodium directly correlates with the amount of water taken in.
Sweat contains only 1 gram of sodium per litre. Physical exertion and humidity will use around 46-92 milligrams of sodium per day. Vomiting and diarrhoea can also leave the body low in sodium, which should be replaced.
Most pre-packaged foods contain high levels of sodium and should be moderated in our diets, so use sparingly. Look at labels and choose the products that have less than 120mg of sodium per 100g.